Latest peizo ceramic PTC direct conduction water Heater available in 300W, 500W, 800W and 1000W sizes to suit 450L, 700L, 900L, 1100L respectively. Efficiency is >95% (wound radiant Heaters ~70%) so you get amazing power savings and phenominal heating speeds (300W will heat 400L @20C to 30C in ~4hrs @ 24C ambient).

Ceramic PTC direct conduction Heater 300W-1000W